Food is a fraught topic. In How Pleasure Works Paul Bloom alludes to the thesis that while conservatives fixate on sexual purity, liberals fixate on culinary purity. For example, is it organic? What is the sourcing? Is it “authentic”? Obviously one can take issue with this characterization, especially its general class inflection (large swaths of the population buy what they can afford). Additionally, I doubt Hindus, Muslims and Jews who take a deep interest in the provenance, preparation, and substance of their food are liberals. What Bloom is noticing is actually a general human preoccupation which somehow has taken on a strange political valence in the United States. Somehow being conservative in this country has become aligned with a satisfaction with the mass-produced goods of the agricultural-industrial complex.* Some conservatives such as Rod Dreher have pushed back against this connotation, lengthily in his book Crunchy Cons.

Stepping away from politics, we are a diet obsessed culture broadly. Apparently Christina Hendricks is going on a diet, her aim being to lose 30 pounds. Diet fads come and go. The Atkins approach has faded of late, with the Paleolithic diet coming into fashion. A totally separate market segment, that of raw food, remains robustly popular. This was obvious when Richard Wrangham came out with Catching Fire: How Cooking Made Us Human; raw food enthusiasts would call in to talk shows where he was a guest, sometimes irritated that Wrangham was claiming that cooking was central to the emergence of modern humanity. His contention that raw food practitioners were healthy precisely because they don’t process as much of their nutritional intake because of the relatively coarse character of what they were consuming was clearly discomfiting to many of them. This is because it is at variance with some of the rationale for their diet. They are not cooking the food in part because they believe that that removes a great deal of nutritive value.

I was thinking about this while reading What is Global History? Offhand the author mentions bread-making as early as 20,000 years go in the process of asserting that many of the preconditions for an agricultural mode of production were already in existence before the end of the last Ice Age. I was surprised by this fact, having never encountered it before. Unfortunately there wasn’t a footnote which I could follow up on, so I thought no more of it. Imagine my curiosity when I stumble upon this paper in PNAS, Thirty thousand-year-old evidence of plant food processing:

European Paleolithic subsistence is assumed to have been largely based on animal protein and fat, whereas evidence for plant consumption is rare. We present evidence of starch grains from various wild plants on the surfaces of grinding tools at the sites of Bilancino II (Italy), Kostenki 16–Uglyanka (Russia), and Pavlov VI (Czech Republic). The samples originate from a variety of geographical and environmental contexts, ranging from northeastern Europe to the central Mediterranean, and dated to the Mid-Upper Paleolithic (Gravettian and Gorodtsovian). The three sites suggest that vegetal food processing, and possibly the production of flour, was a common practice, widespread across Europe from at least ~30,000 y ago. It is likely that high energy content plant foods were available and were used as components of the food economy of these mobile hunter–gatherers.

“It’s like a flatbread, like a pancake with just water and flour,” said Laura Longo, a researcher on the team, from the Italian Institute of Prehistory and Early History.

“You make a kind of pita and cook it on the hot stone,” she said, describing how the team replicated the cooking process. The end product was “crispy like a cracker but not very tasty,” she added.

The contents of the paper are somewhat dry and opaque to me. The crux of the matter is that there are obviously important reasons why plant materials which may have been present in prehistoric camps aren’t preserved, so there has long been a bias in this area. It seems that the authors found a primitive system of pestle grinders, as well as flour grains. Below are the important figures which show their results:

no images were found

The Reuters piece takes a shot at the Paleolithic diet:

The researchers said their findings throw humankind’s first known use of flour back some 10,000 years, the previously oldest evidence having been found in Israel on 20,000-year-old grinding stones.

The findings may also upset fans of the so-called Paleolithic diet, which follows earlier research that assumes early humans ate a meat-centered diet.

I don’t know how the Paleo enthusiasts will react to this. I’m actually a guarded fan of Gary Taubes 2002 article in The New York Times MagazineWhat if It’s All Been a Big Fat Lie? I believe that a strong bias toward refined carbohydrates in your diet is bad for you. I generally don’t go as far as the Paleo enthusiasts in my own diet, but I have many friends who believe in the diet, and it works for them. That being said some of the Paleo people have an evangelistic aspect that probably is the source of shots like the ones above in the article. I am 5’8 and in the 140-150 range, usually in the 140-145 range. I’m not fat, and I’m not Paleo. My blood sugar levels are good. It can be done. Just because you were fat or or unfit and a particular diet works for you doesn’t mean everyone else has to follow the exact same prescription to the T. Human variation matters. South Asians have much higher propensities toward type 2 diabetes than other groups. It follows from that that everyone need not follow the nutritional and lifestyle guidelines of South Asians to get the same odds ratio of developing type 2 diabetes. How guilty you should feel about dessert is a function of the biological cards you bring to the table.

The importance of human variation, genetically and culturally, is relevant to this paper. What exactly does the likely presence of flour in three sites in Europe ~30,000 years ago tell us? Granting the validity of these results we can reject a strong form of the model of a Paleolithic diet which excluded processed starches. Does this now mean that Paleolithic humans were toasting pitas constantly around the fire? I don’t necessarily think so. We don’t know how pervasive this practice was. Human societies vary. Just because they were ancient, and “primitive,” does not mean that all Paleolithic populations were all the same. Second, it sees plausible that Paleolithic man was a generalist with a more diversified diet, all things equal, than his peasant successors. It may be that during the Paleolithic era there were no staples in a way we’d understand it today, rather, they subsisted on what was available at any given time. Perhaps these ancient pitas were reserve sources of sustenance which preserved well when other gathering and hunting had little or no yield. The difference between the Paleo-man and the peasant may then be thought of as the latter making what was once an emergency ration which was a good source of calories in a pinch into the staff of life.

A more general moral may be that we need to rethink our model of a Neolithic Revolution. It may have been a Neolithic Evolution. After the last Ice Age there were at least two independent, and likely more than two, domestication events and shifts toward an agricultural lifestyle. In The Long Summer and After the Ice Brian Fagan and Steven Mithen both imply that the emergence of behavioral modernity during the last Ice Age set the stage for the inevitable shift toward agriculture with the climatic change. So was it was (warm weather) + (modern cognitive capacity) → agriculture? Perhaps. But almost certainly humans were developing skills and competencies over time up until the end of the Ice Age, and with the warmer conditions the switch toward more proactive and intensive cultivation of grains may have been a gradual process of escalation. As population densities began to rise it seems a model could be posited whereby a positive feedback loop was being generated; non-agriculture sidelines were less and less effective as larger populations supported by semi-agricultural lifestyles made greater demands on the local ecology. This may have meant that the shift toward obligate agriculture was inevitable once it became the only viable option. Once the ratchet moved forward there was no going back, and humans had entered a new epoch.

Today we live in a consumer age of plentitude. Or at least you live in a consumer age of plentitude if you’re reading this weblog on a computer. We have great choice in goods and services, and can have a wide range of experiences. The past was truly a strange and exotic place; as evidenced by the reality that pre-modern folk took high infant mortality for granted as an unfortunate fact of life, while we today see the death of an infant as a tragedy of the highest caliber. But we mustn’t oversimplify the past. In one episode of the 1989 television series Alien Nation the human protagonist is learning about the religious customs of his partner, an alien. Offhand he mentions his growing awareness to another acquaintance who is also an alien. He then asks if she will be celebrating a holiday he has just learned of, and she responds that she does not believe in that religion. The detective expresses great surprise that the aliens have different religions, to which she quips, “Don’t you?” The point is that the aliens are perceived as an amorphous mass, profoundly different from humanity, and their own internal distinctions are elided in the minds of humankind. And so I believe occurs with human societies of modes of production fundamentally different from our own. “Paleolithic humanity” becomes a type, all difference and variation removed from our conception. “Hunter-gatherer” is distilled down to an image of N!xau from The Gods Must Be Crazy. To get a better handle of how the world is and how it was we need to be careful of this cognitive bias.

* Just to be clear, I am not personally an unalloyed enthusiast for “natural” methods, whether it be organic or small-scale farming. Rather, I am pointing to the fact that agricultural subsidies have distorted and reshaped the nature of food production, distribution, and consumption. I see nothing fundamentally conservative about being sanguine about the power and influence of the agricultural-industrial lobby, and the corporations which exist in symbiosis with government largesse.

Image Credit: Wikimedia Commons, Serious Eats

Note: Since this post mentions diet I may get some crazy unhinged comments because I know that some people take their diets very seriously, and react harshly to deviationists from the Truth Path. If you have commenting privileges and lose control and post something inappropriate, I will delete it.

Reading the first sentence of the PNAS paper shows that the authors ASSUME the make-up of a paleolithic diet. They assume incorrectly. The paleolithic diet included plenty of vegetables and roots. A diet of only animal fat and protein is not possible.

Further inspection shows the ingredients for the ‘flour’ is mostly roots and NOT grains.

This paper starts out with a bad assumption and their own data contradict the conclusions. This is then taken to absurdity by media sources.

Soup can be wonderful food, delicious, nutritious, warming and a good way of using up scraps of this-and-that. When did humans first have equipment that let them make soup? Pottery? Or something earlier?

Sandgroper

I’m unclear on why this should have come as a surprise. I realize that hunter-gatherer behaviour is likely environment-specific and shouldn’t be generalised, but Australian Aboriginal people were obviously a late-Pleistocene people, and they had this practice, which was copied by white stockmen and drovers after European settlement, substituting wheat flour for native plant foods.

Aborigines had no agriculture, but did selectively clear plants to encourage increased growth of seed and nut bearing plants in areas that they would return to repetitively to harvest. So they were part-way towards developing agriculture, as Jared Diamond noted.

Aboriginal advocates encourage their people to return to a diet of “bush tucker” to try to combat obesity, high blood pressure, heart disease and Type 2 diabetes, which they suffer from disproportionately.

dave chamberlin

bioIgnoramus asks a good question which I shall change slightly. He asks when did humans first have equipment that let them make soup? What I will ask and then answer is when could humans first boil water? The answer is somewhat suprising, as soon as man had the hides of animals. A flamable material will not burn if it is filled with water until the water is completely boiled away. You can fill a styrofoam cup full of water and place it into a hot fire and it will not burn or melt until the water is boiled away. Go ahead and try it next time you go camping.

Any of those goofy survival shows has these stranded tough guys (and their camera crews) out in the middle of nowhere obsessed with finding water and then sterilizing it. I was suprised to read Richard Wranghams “Catching Fire, How Cooking Made us Human” and not see him play up the importance of fire in this very key role, namely killing harmful bacteria in food and water.

http://www.terryballard.org Terry Ballard

This is interesting stuff. I’ve been on the paleo diet now for six months, leaving behind a serious addiction to bread and pasta. I’m on a somewhat modified plan, still eating potatoes and the occasional sushi, but the health benefits so far have been spectacular. Lost a bit of weight and a whole lot of abdominal bloat. Haven’t snored since the day I went paleo, and use my asthma inhaler much less. So, whether or not cavemen pounded out flour in their caves, I’m sticking with this for the simple reason that it works for me, and I don’t miss pizza as much as I thought I would.

Razib, Jews, Muslims and Hindus who obsess about what is in their food may not be liberal, but the liberal association with preference for food being “natural” and “organic” and not “processed, evil, factory-made” is widespread among those who are fortunate enough to reach upper-middle class status in third world countries. In fact, since it dovetails with wider anti-western (“anti-imperialist”, “post-colonial”) opinions, it may be proportionally greater in those countries (a hatred for “frankenfood” being a way of taking a stand against imperialism and ne0-colonialism without having to join the taliban). You would be surprised (well, maybe not surprised) to see the number of organic food stores and whole-earth type businesses in the richer sections of Islamabad or Lahore. …and in Pakistan (and maybe India and BD, for all I know) the liberal upper middle-class enjoys their internet-based “knowledge” about the reality of modern food without letting any facts get in their way (I am not saying factory-food is all good or all their “facts” about the hazards of pork and white sugar are wrong, just that the conversations I have with friends in Pakistan are science-free and evidence-resistant to a most remarkable degree)….

Katharine

The difference between conservative ideas of sex and liberal ideas of food is that generally, I’ve never seen most liberals try to put into law anything condemning people who eat battery hen eggs and consume foie gras and saying they can’t eat at public restaurants.

http://occludedsun.wordpress.com Caledonian

A diet of only animal fat and protein is not possible.

Thank goodness you stopped by. Inuit have been subsisting on a diet composed almost entirely of animal fat and protein for thousands of years – imagine if you hadn’t shown up to let them know their way of life was unsustainable!

the inuit retrieve vegetable material from the guts of some of the animals they eat.

I’ve never seen most liberals try to put into law anything condemning people who eat battery hen eggs and consume foie gras and saying they can’t eat at public restaurants.

there are now laws about cages in california i believe.

omar

And there are laws or attempts at laws to ban foie gras. There are also attempts to ban salt, ban trans fats (which i agree are really not good for you), tax “unhealthy foods” and so on…..I consider myself liberal and dont like conservatives trying to impose their likes and dislikes on everyone, but just wanted to point out that the impulse is not restricted to conservatives.
Whether a law actually makes it to the books does depend on the strength of the lobbies supporting it or opposing it, and the food police are clearly a smaller and less powerful lobby than the Evangelical Christians, but they do try…

http://www.arthurdevany.com Arthur De Vany

The inuit also eat abundant amounts of fat. American Indians also eat the stomach contents of many animals. All hunter-gatherers retrieve vitually all the fat, including the lipoproteins in the bone marrow, so they have ample vit A and the other energy substrates a avoid protein posioning. which is quite rare. This is an old hack with scant evidence to back it up. A little brain tissue is all an Paleolithic forager would require to avoid protein poisoning. In most foraging environments, but for the deepes Ice Ages, there were at least 300 plants available and known.

Optimal foraging theory says the grains would have been far down the food chain; so it is likely these were stressed populations. Besides, the dating has not been looked into and the study has to meet the criticism from scientists before this aspect of early diet can be taken seriously. Even the wording in the title is meant to provoke; there was no food pyramid and to say there was one endows the present un-scientific pyramid, a mismash of bad advice according to some scientists, with more respect than it is due.

omar

Arthur, You are absolutely correct. About protein poisoning, it does seem that there is a ceiling of around 35-40% of calories from protein, more that may be hard for the kidney to handle. Eating a lot of fat is key. Veggies were around in most environments, but minimal for the Innuit (though they got some seaweed). There was someone who did a research study in New York where he only ate meat and fat and did OK, but I will have to dig up the reference. The contents of animal stomachs were eaten, but may not have been a significant source of anything for the Innuit. Refined grains in the amounts now consumed are clearly a late addition to our diet though occasional small populations may indeed have relied on them a very long time ago too.
Razib, Gary Taubes’s article (what if its all been a big fat lie) is indeed excellent but he has taken a turn towards increasingly aggressive low-carb theorizing in his book “good calories bad calories” and his own science seems occasionally suspect (the belief that insulin is the key to the obesity epidemic is taken to extremes that the data does not support).

http://blogs.discovermagazine.com/gnxp Razib Khan

re: low-carb extremism, etc., yeah, that’s why i don’t take any of the stuff to heart too much, but practice moderation. though i do think that we’re cranked the dial up so far on sugar and refined carbs in our society that anti-carb extremism is useful.

I think the paleo diet is a useful but flawed heuristic. It is useful in the sense that it makes intuitive sense for most people and improves health and performance over a Standard American or Vegetarian diets.

The problem is that it is based on fallacious logic we know that we have in fact continued to evolve since the paleolithic and our models for paleolithic nutrition are flawed as Razib’s note any model that tries to cover all the variation of 1.5 millions years of human evolution and much of the world is going to painting in very broad strokes indeed. Finally working better then bad approaches like the SAM or Vegetarian diet does not imply optimization.

I think nutrition indeed health and performance in general needs to be understood within an evolutionary context but we need to be cautious about jumping to conclusions and painting just so stories without strong data. I tend to talk to people about evolutionary or ancestral approaches to diet as opposed to cavemen.

I don’t think this particularly study tells us much that should shift our priorities in optimizing diet.

We already knew hunter foragers would gather seeds and make breads out of them before. Prior to agriculture there is not allot of evidence this was a staple food source. The question of how adapted we are to eating grains is still an open to question and there is strong reason to believe in population and individual variation in how strong that adaption is. Just as there is for Dairy.

With our athletes, everyone seems to respond well to high levels of animal fat and protein, most people of European decent do great with dairy, grains are more hit or miss but if the athletes don’t do grains, we use allot of sweet potatoes, without a good source of starch it is very difficult to get athletes to gain muscle and their tolerance for weekly volume of exercise goes down.

You are a brave man to take on the topic of diet! Many thanks. As you know, I follow a paleo/ low carb diet, enjoy it as it has done my health good. I mention my diet to others in poor health or hoping to loose weight.

What is strange to me, is that for what ever reason it is frequent for others to try and get me to eat bread. I think I even had someone on TV offering me cookies this afternoon! He was spiking his blood sugar he added. That made me laugh. There are many more health issues with wheat and grains than just blood sugar spikes! As you mention also about the diet aspect of liberal verses conservative, I read an article last month in a conservative magazine saying to the effect that liberals eat as I do. It wasn’t exactly stated that way, but that was the opinion I gleaned. Rather surprised me.

I lean libertarian anyway, as do most paleo and low carb followers I’ve found, and with this broke government, subsidies for grains should stop as far as I’m concerned. Eating less grains would be good for the health of many I suspect, better for lowering government costs, and in addition help poor nation’s farmers that are not able to compete with America in agriculture.

I wonder what the fate of the paleo or low carb diet will be in the future. I think the paleo diet probably will remain with us – my guess at least. It won’t be a fad. I believe that, simply, because of the better health it provides for those that follow it. Eating low carb or paleo leaves you with a good feeling, unlike other diets which can leave one hungry and tired. It is nice now that people are not frightened from these diets, as occurred in the past. The scare being that heart disease, cancer or kidney damage was likely if a low carb/ Atkins/ or paleo diet was eaten. Today with Gary Taubes and other health care leaders leading the way, these diets are thought of as equals or even healthier than other popular diets, – vegetarian or vegan.

A problem of course is what you mention, some find paleo people to be annoying. Basically people knit-pick at the science, with out trying the diet. I think basically others often don’t want to give up convenience fast foods, and to be honest, I can’t blame them.

Maybe Unilever possibly coming out with ready made paleo dishes isn’t such a bad thing.

http://blogs.discovermagazine.com/gnxp Razib Khan

excellent post by robin!

As you know, I follow a paleo/ low carb diet, enjoy it as it has done my health good. I mention my diet to others in poor health or hoping to loose weight.

i don’t know you, do i?

A problem of course is what you mention, some find paleo people to be annoying. Basically people knit-pick at the science, with out trying the diet. I think basically others often don’t want to give up convenience fast foods, and to be honest, I can’t blame them.

i can’t speak for others, but i don’t east fast food. rather, if i mention that i’ve had pasta or something my paleo-acquaintances are liable to point out that i’ve transgressed. that’s how it feels, as if it’s a purity test. i eat mostly protein, fats, and vegetables myself, and very little sugar. i avoid processed foods. i do on occasion east pasta, but generally whole grain ones. as i said above, my health is good re: blood sugar, blood pressure, weight, waist, etc. so what’s the complaint? i grant that some people do have issues with impulse control and very stringent rules are necessary. i’m not one of those (i don’t crave sugar for example for whatever reason, so if i indulge in a condiment which may have sugar it doesn’t mean i’m off the train).

Katharine

Well, you don’t see widespread banning of meat-eaters from public restaurants, either.

http://tispaquin.blogspot.com Doug Watts

The reference to ‘cavemen’ is really stupid. Nobody in their right mind ever lived in caves. They only went to them to make paintings. Why would anyone live in a cave, especially where there are no caves?

http://blogs.discovermagazine.com/gnxp Razib Khan

it’s a cultural reference dumbshit.

Sandgroper

Everyone but Rafe has ignored the elephant in the room – physical activity and goals. The last decent data I saw on this suggested a strength athlete trying to gain muscle mass needs carbs to protein in the ratio of 4:1.

Easy to remember, and all of it negotiable. Best of all, no wingnut justifications about how it’s evolutionarily, spiritually, morally, or cosmically correct. If you want to live as long as possible, the only sure-fire way is borderline starvation levels of caloric intake, regardless of source. I happen to think we live too long (or at least other people do). Unfortunately I have a weakness for the Trader Joe’s sugar aisle, and drink fruit juice by the liter. I only fluctuate in like a 5-pound range, but it is fast and totally dependent on sticking to the above.

Sandgroper

I’ll just note that Mexico is the most obese nation on earth.

http://blogs.discovermagazine.com/gnxp Razib Khan

If you want to live as long as possible, the only sure-fire way is borderline starvation levels of caloric intake, regardless of source

Miko how is your system more rational then the ones you deride as wingnut, what is your rationale. Why whole grains on the list but no meat? Why no HFCS but you use sugar, you do realize they are composed of the same base elements which your digestion quickly breaks them down to right? Fruit juice for that matter is basically fructose syrup without any of the absorption slowing effects of the fiber of the fruit?

Its also important to note that there are more reason to focus on diet then life extension. In a word quality of life, good diet aids athletic performance, mental performance, and sexual performance. Those are important to me.

Sandgroper that figure is pretty extreme and assumes a much lower level of fat intake then we use with most of our athletes. I don’t think there is any real evidence to show specific macronutrient breakdowns are optimal for mass gain.

Sandgroper

Yeah, it’s a fairly old figure that assumes a low fat intake.

http://thebodyyouwant.com Josef Brandenburg

Great piece.

Somebody made the good point that they mention plants, but not grains in the article. Also, 30k isn’t that much longer than 10k. Even if it were grain 30k yrs ago, it is still a very new food.

Fascinating reading. For me the paleo diet has been wonderful. I’ve lost 20 lbs and feel more healthy than I have for years. The reason I chose paleo diet was because of the gluten free aspect as I have celiac disease. So if cavemen ate bread or not its really of no importance to me!
great article and really interesting comments.

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Gene Expression

This blog is about evolution, genetics, genomics and their interstices. Please beware that comments are aggressively moderated. Uncivil or churlish comments will likely get you banned immediately, so make any contribution count!

About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at http://www.razib.com